Evaporation Boats: Essential Tools in Thin Film and Metallization Technology

Evaporation boat are critical components in various industrial and scientific processes involving vacuum deposition, particularly in the manufacturing of thin films. Though they may seem like simple devices at first glance, their role is crucial in high-precision applications such as electronics, optics, packaging, and solar energy.

In this article, we will explore what evaporation boats are, how they work, the materials used to manufacture them, and their widespread applications across high-tech industries.

1. What is an Evaporation Boat?

An Evaporation Boat is a specialized container or vessel used in thermal evaporation processes under vacuum conditions. These boats are designed to hold and heat materials (usually metals) until they evaporate. The resulting vapor then condenses onto a substrate, forming a thin and uniform film.

They are commonly used in physical vapor deposition (PVD) techniques for metallization or coating applications.

2. How Do Evaporation Boats Work?

The working principle of an evaporation boat is straightforward but requires precision:

  1. Material Loading: The source material (e.g., aluminum, silver, or gold) is placed inside the boat.
  2. Heating: The boat is electrically heated via resistive heating or induction, reaching temperatures high enough to melt and then evaporate the material.
  3. Evaporation: In a vacuum chamber, the molten material turns into vapor due to the lowered boiling point under low pressure.
  4. Deposition: The vapor particles travel through the vacuum and settle onto a cooler surface (substrate), forming a thin, uniform film.

This method is highly efficient and allows for precise control of the film’s thickness and composition.


3. Materials Used in Evaporation Boats

Evaporation boats must withstand extremely high temperatures and maintain chemical stability while conducting electricity. The most common materials include:

a. Boron Nitride (BN)

b. Titanium Diboride (TiB₂)